To enable the efficient elimination or controlling of unwanted pests, it is desirable to use effective chemical pesticides on these unwanted pests. Soluble granule formulations containing water-soluble pesticides are desirable in agricultural and related endeavors due to ease of handling and the elimination of organic solvents, which can be costly and dangerous to the environment. Safety, specifically eye irritation, caused by solvents, dispersants, clays and wetting agents in traditional formulations are also of concern. In addition, the process used to make the soluble granule formulation can be conducted in relatively simple equipment using relatively simple process steps.
The formulation of soluble granule pesticides has been disclosed in the prior art, for example in U.S. Pat. No. 6,387,388 (Misselbrook et al.). Challenges in formulating a soluble granule of a water-soluble pesticide include the requirements that the final product successfully achieves (a) good dispersibility/solubility in an aqueous medium and (b) chemical stability once dispersed.
Good dispersibility/solubility in an aqueous medium is important in a soluble granule formulation since ineffective mixing of the pesticide into solution can result in reduced or inconsistent efficacy and, ultimately, costly returns of product and loss of sales. Chemical degradation is also important because there may be no physical sign of the degradation and resultant loss of efficacy until used on a pest. Examples of problematic chemical degradation include hydrolysis, oxidation, dehalogenation and bond cleavage.